1. Field of the Invention
The present invention relates to a line branching printed circuit board for a computer numerical controller, and more particularly, to a line branching printed circuit board for a computer numerical controller which permits an easy change of the branching of input/output signal lines between a computer numerical controller and a numerically controlled machine tool.
2. Description of the Related Art
The input/output signal lines between a computer numerical controller and a numerically controlled machine tool are branched on the way from an input/output circuit of the computer numerical controller to the individual control circuits of the numerically controlled machine tool.
Conventionally, such a line branching is made on a line branching panel, and the terminals of the line branching panel are wire-wrapped for connection, but currently, line branching printed circuit boards are used to branch signal lines. The use of a line branching circuit board eliminates erroneous connections and permits an easy line branching, and therefore, line branching printed circuit boards are extremely advantageous particularly when producing standardized products or for mass production.
As mentioned above, when an input/output signal line between a computer numerical controller and a numerically controlled machine tool was branched using a conventional line branching panel, the terminals of the line branching panel were wire-wrapped for connection. This required skill and time, and further, were liable to result in an erroneous connection.
Also, in the conventional line branching printed circuit board for a computer numerical controller, the pins of a particular connector of the input/output signal line of the computer numerical controller are keyed to and connected to the pins of a particular connector of the input/output signal line of the numerically controlled machine tool, because of a pattern-based connection, and accordingly, the input/output signal lines between the computer numerical controller and the numerically controlled machine tool are fixed. Therefore, if it becomes necessary to increase the number of the input/output signals between the computer numerical controller and the numerically controlled machine tool, or to change the signal route, then the pattern on the line branching printed circuit board must be cut and a plating wire must be soldered to the pattern by hand, and thus any change in the branching of an input/output signal line takes much time.